CODEWITHSUNDEEP
matlablinear-algebrasvd
kenneth
kenneth

Reputation: 167

svd value different between matlab 2011b and 2012b

i try to implement the same matrix F to the svd function on both versions of matlab. However, i found out that sign of U and V matrix from both solutions are opposite. May i know which versions of MATLAB provide a better or more accurate answer? or actually both answers are correct?

Upvotes: 0

Views: 617

Answers (1)

Sam Roberts
Sam Roberts

Reputation: 24127

The singular value decomposition of a matrix is only defined up to a sign, so the signs of U and V are arbitrary, and both answers are correct. Whichever signs MATLAB produces, it should still be the case that F = U*S*V, so U and V constitute a correct singular value decomposition of F. (Note "a", not "the").

You shouldn't rely on MATLAB producing particular signs, and it may vary from version to version.

Upvotes: 1

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